FFmpeg
tscc.c
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1 /*
2  * TechSmith Camtasia decoder
3  * Copyright (c) 2004 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * TechSmith Camtasia decoder
25  *
26  * Fourcc: TSCC
27  *
28  * Codec is very simple:
29  * it codes picture (picture difference, really)
30  * with algorithm almost identical to Windows RLE8,
31  * only without padding and with greater pixel sizes,
32  * then this coded picture is packed with ZLib
33  *
34  * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
35  */
36 
37 #include "avcodec.h"
38 #include "codec_internal.h"
39 #include "decode.h"
40 #include "msrledec.h"
41 #include "zlib_wrapper.h"
42 
43 #include <zlib.h>
44 
45 typedef struct TsccContext {
46 
49 
50  // Bits per pixel
51  int bpp;
52  // Decompressed data size
53  unsigned int decomp_size;
54  // Decompression buffer
55  unsigned char* decomp_buf;
57  int height;
59 
60  uint32_t pal[256];
61 } CamtasiaContext;
62 
63 static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
64  int *got_frame, AVPacket *avpkt)
65 {
66  const uint8_t *buf = avpkt->data;
67  int buf_size = avpkt->size;
68  CamtasiaContext * const c = avctx->priv_data;
69  z_stream *const zstream = &c->zstream.zstream;
70  AVFrame *frame = c->frame;
71  int ret;
72  int palette_has_changed = 0;
73 
74  if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
75  palette_has_changed = ff_copy_palette(c->pal, avpkt, avctx);
76  }
77 
78  ret = inflateReset(zstream);
79  if (ret != Z_OK) {
80  av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
81  return AVERROR_UNKNOWN;
82  }
83  zstream->next_in = buf;
84  zstream->avail_in = buf_size;
85  zstream->next_out = c->decomp_buf;
86  zstream->avail_out = c->decomp_size;
87  ret = inflate(zstream, Z_FINISH);
88  // Z_DATA_ERROR means empty picture
89  if (ret == Z_DATA_ERROR && !palette_has_changed) {
90  return buf_size;
91  }
92 
93  if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
94  av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
95  return AVERROR_UNKNOWN;
96  }
97 
98  if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
99  return ret;
100 
101  if (ret != Z_DATA_ERROR) {
102  bytestream2_init(&c->gb, c->decomp_buf,
103  c->decomp_size - zstream->avail_out);
104  ff_msrle_decode(avctx, frame, c->bpp, &c->gb);
105  }
106 
107  /* make the palette available on the way out */
108  if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
109  frame->palette_has_changed = palette_has_changed;
110  memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
111  }
112 
113  if ((ret = av_frame_ref(rframe, frame)) < 0)
114  return ret;
115  *got_frame = 1;
116 
117  /* always report that the buffer was completely consumed */
118  return buf_size;
119 }
120 
122 {
123  CamtasiaContext * const c = avctx->priv_data;
124 
125  c->avctx = avctx;
126 
127  c->height = avctx->height;
128 
129  switch(avctx->bits_per_coded_sample){
130  case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
131  case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
132  case 24:
133  avctx->pix_fmt = AV_PIX_FMT_BGR24;
134  break;
135  case 32: avctx->pix_fmt = AV_PIX_FMT_0RGB32; break;
136  default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
137  return AVERROR_PATCHWELCOME;
138  }
139  c->bpp = avctx->bits_per_coded_sample;
140  // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
141  c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
142 
143  /* Allocate decompression buffer */
144  if (c->decomp_size) {
145  if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
146  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
147  return AVERROR(ENOMEM);
148  }
149  }
150 
151  c->frame = av_frame_alloc();
152  if (!c->frame)
153  return AVERROR(ENOMEM);
154 
155  return ff_inflate_init(&c->zstream, avctx);
156 }
157 
159 {
160  CamtasiaContext * const c = avctx->priv_data;
161 
162  av_freep(&c->decomp_buf);
163  av_frame_free(&c->frame);
164  ff_inflate_end(&c->zstream);
165 
166  return 0;
167 }
168 
170  .p.name = "camtasia",
171  CODEC_LONG_NAME("TechSmith Screen Capture Codec"),
172  .p.type = AVMEDIA_TYPE_VIDEO,
173  .p.id = AV_CODEC_ID_TSCC,
174  .priv_data_size = sizeof(CamtasiaContext),
175  .init = decode_init,
176  .close = decode_end,
178  .p.capabilities = AV_CODEC_CAP_DR1,
179  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
180 };
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
GetByteContext
Definition: bytestream.h:33
TsccContext::height
int height
Definition: tscc.c:57
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:116
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVPacket::data
uint8_t * data
Definition: packet.h:374
TsccContext::gb
GetByteContext gb
Definition: tscc.c:56
FFCodec
Definition: codec_internal.h:119
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
TsccContext::frame
AVFrame * frame
Definition: tscc.c:48
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
TsccContext::zstream
FFZStream zstream
Definition: tscc.c:58
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
TsccContext::decomp_size
unsigned int decomp_size
Definition: tscc.c:53
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
inflate
static void inflate(uint8_t *dst, const uint8_t *p1, int width, int threshold, const uint8_t *coordinates[], int coord, int maxc)
Definition: vf_neighbor.c:195
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:104
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
zlib_wrapper.h
av_cold
#define av_cold
Definition: attributes.h:90
TsccContext::avctx
AVCodecContext * avctx
Definition: tscc.c:47
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
ff_tscc_decoder
const FFCodec ff_tscc_decoder
Definition: tscc.c:169
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:363
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
if
if(ret)
Definition: filter_design.txt:179
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
msrledec.h
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: tscc.c:63
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:353
codec_internal.h
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: tscc.c:158
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1444
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: tscc.c:121
AV_PIX_FMT_RGB555
#define AV_PIX_FMT_RGB555
Definition: pixfmt.h:447
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
ff_inflate_end
void ff_inflate_end(FFZStream *zstream)
Wrapper around inflateEnd().
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1568
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
AV_PIX_FMT_0RGB32
#define AV_PIX_FMT_0RGB32
Definition: pixfmt.h:436
TsccContext
Definition: tscc.c:45
AVCodecContext
main external API structure.
Definition: avcodec.h:398
TsccContext::pal
uint32_t pal[256]
Definition: tscc.c:60
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
FFZStream
Definition: zlib_wrapper.h:27
AV_CODEC_ID_TSCC
@ AV_CODEC_ID_TSCC
Definition: codec_id.h:108
TsccContext::bpp
int bpp
Definition: tscc.c:51
ff_msrle_decode
int ff_msrle_decode(AVCodecContext *avctx, AVFrame *pic, int depth, GetByteContext *gb)
Decode stream in MS RLE format into frame.
Definition: msrledec.c:249
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AVPacket
This structure stores compressed data.
Definition: packet.h:351
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
ff_inflate_init
int ff_inflate_init(FFZStream *zstream, void *logctx)
Wrapper around inflateInit().
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
ff_copy_palette
int ff_copy_palette(void *dst, const AVPacket *src, void *logctx)
Check whether the side-data of src contains a palette of size AVPALETTE_SIZE; if so,...
Definition: decode.c:1666
TsccContext::decomp_buf
unsigned char * decomp_buf
Definition: tscc.c:55